error c2450:switch expression of type 'float' is illegal

This error message is generated by the C++ compiler when a switch statement is used with a float type variable as its expression. In C++, switch statements can only be used with integral types such as int, char, and long.

To resolve this error, you can either convert the float variable to an integer using a type casting operator or change your code to use an if-else statement instead of a switch statement.

For example, instead of using:

float x = 2.5;
switch(x) {
   case 1.0:
      // do something
      break;
   case 2.0:
      // do something else
      break;
   default:
      // handle other cases
      break;
}

You can use:

float x = 2.5;
int y = static_cast<int>(x); // convert float to int
if(y == 1) {
   // do something
}
else if(y == 2) {
   // do something else
}
else {
   // handle other cases
}